The present invention relates generally to a wiper arm for windshield wipers of a vehicle Known windshield wipers have a wiper arm, which is made up of a fastening element and a hinge part, which is pivotably connected to it via a swivel joint and has a wiper rod. A hooklike end of the wiper rod engages a suspension box of a wiper blade, which is formed by two side cheeks of a middle bracket and includes a hinge bolt The hinge thus formed guides the wiper blade over the vehicle window during the swiveling motion. The wiper blade has what is as a rule a multi-member support bracket system, with subordinate brackets pivotably connected to the middle bracket, at least some of which subordinate brackets, with claws on their ends, retain a wiper strip by its head strip. The multi-member support bracket system and spring rails plated in the head strip make it possible during wiping for the wiper strip to adapt, with a uniform contact pressure, to a curved windshield. To that end, a tension spring prestresses the swivel joint.
Such windshield wipers are known, for instance from German Patent Disclosure DE 37 44 237 A1. In simple versions, subordinate brackets, also known as intermediate brackets and claw brackets, can be dispensed with. In the simplest case, the middle bracket itself has claws, with which it retains the wiper strip. Windshield washing systems for vehicles are as a rule used in conjunction with windshield wipers. They are actuated if the moisture from precipitation does not suffice to clean the vehicle window. They include a water container, spray nozzles, and a pump, which pumps water, sometimes admixed with cleaning and antifreeze agents, under pressure out of the water container to the spray nozzles.
It is already known for spray nozzles to be secured as additional components to the wiper blade and thus for the spray water to be distributed over the wiping region directly with a short length of stream. Since the spray water is concentrated on a region in the vicinity of the wiper blade and is washed off again within the shortest possible time by the wiping motion, the view is hindered only briefly by the spray water applied. One disadvantage of such systems is that the effects of weather, especially hail and strong sunshine, greatly affect the flexible parts of this arrangement, which are needed for spanning the hinged regions between the wiper arm and the wiper blade. Furthermore, the spray nozzles and water lines, which are exposed to the relative wind, rapidly freeze closed at temperatures below the freezing points, unless antifreeze is admixed with the water. Frozen water lines and spray nozzles can be defrosted again as a rule only with great effort.
It is also known for spray nozzles to be solidly integrated with the wiper arm, for instance the connection piece to the wiper blade or the fastening element secured to the drive shaft. If the spray nozzles or the water supply lines fail from being stopped up, broken, or the like, then the complete wiper arm has to be replaced.
In an earlier German Patent Application, DE 198 15 171.3, a wiper arm is described on the hinge part of which, or a wiper rod integrally connected to the hinge part, spray nozzles are disposed. The spray nozzles are located in a nozzle body, which is accommodated in a bulge of the hinge part that has an injection opening for the spray stream, or is clipped, protruding downward, in a lateral mount on the wiper rod. It is also possible for two nozzle bodies to be provided, which are joined to one another by means of a rigid or flexible connecting piece. The nozzle bodies are easily replaced and are well protected from environmental factors.
A heating device, passed in the form of a wire through a water supply line and embodied as a heating coil in the nozzle body, is integrated into the arrangement of spray nozzles. Simple versions are obtained by providing that the nozzle bodies are integrally joined together and are produced from plastic as an injection-molded part. By means of the nozzle bodies distributed along the wiper arm, the spray water is well distributed over the wiping region, especially if a spray stream is directed into a lower region directly in front of the wiper blade. Since this arrangement results in short stream lengths, the relative wind can have only little effect on spray water distribution, even at a relatively high vehicle speed. Because of the different ways they are fastened to the hinge part or the wiper rod, the nozzle bodies are fundamentally designed differently, so that for the most various wiper arms, numerous variant forms of nozzle bodies must be made available. Furthermore, the arrangement of spray nozzles and the orientation of the spray streams are limited by the shape and orientation of the hinge part relative to the wiper blade.
According to the invention, the spray nozzles are let into a lower portion of a nozzle body that is inserted into the U-shaped profile of the wiper arm. The lower part of the nozzle body protrudes, toward the field to be wiped, out of the hinge part or the wiper rod. It serves above all for the disposition of the spray nozzles and is largely independent of the design of the particular wiper arm or the wiper rod formed onto it. The spray nozzles can be disposed on the long side, located in the starting direction of the wiper arm, or on the face end located longitudinally of the wiper arm, and/or on the bottom of the nozzle body. At least one of the spray streams of these spray nozzles is expediently oriented at a small angle a to the wiper blade and meets the wiping field in the region of the inner circle of the wiper blade. Providing a spray nozzle on the face end or bottom is especially advantageous in the case of windshield wipers in which the wiper arm is offset from the wiper blade in the starting direction. The spray streams can thus be oriented approximately parallel to the wiper blade. They are protected from the relative wind on side by the wiper blade and from above by the hinge part and the wiper rod, and they reach the wiping field with a short stream length, so that the relative wind has hardly any influence on the distribution of spray water over the wiping field.
The upper part of the nozzle body serves to mount it in the U-shaped profile of the hinge part or of the integrated wiper rod; on its long sides, the nozzle body has bearing faces with which it rests on the face ends of the side walls of the U-shaped profile. The nozzle body can be retained in the U-shaped profile by nonpositive engagement, in that a lateral spring tongue is braced on the side wall of the hinge part and presses the nozzle body against the opposite side wall. The spring tongue can be designed such that the nozzle body is suitable for different widths of U- shaped profile and can also be retrofitted into existing windshield wipers.
The nonpositive engagement can be replaced by a positive engagement or can be supplemented by snapping the spring tongue into an opening of the side wall or having it engage a heel, on the adjacent side wall of the hinge part in the region of the nozzle body, from behind. This heel can be formed by an inward-bent part of the side wall of the hinge part or the wiper rod. On the side opposite the spring tongue, the nozzle body expediently rests on the side wall with a bead extending longitudinally. Because of the linear contact, the nozzle body can rest flush with its bearing faces on the side walls of the hinge part or wiper rod, regardless of any angle tolerances on the U-shaped profile.
In principle, it suffices if only one nozzle body is disposed in the region of the hinge part. However, for better distribution of the spray water, two nozzle bodies are advantageous, either accommodated spaced apart from one another in a long hinge part, or with one of them disposed in a hinge part and the other in a wiper rod that is formed integrally onto the hinge part.